Apparatus, system and method for dovetail locking mechanisms

ABSTRACT

An apparatus, system and method for dovetail locking mechanisms are described herein. A system for locking the dovetail of a trailer in the travel position includes a sled for locking the dovetail of a trailer in the travel position, a railing on the underside of the trailer to accommodate the sled, wherein the sled is moveably attached to the railing such that the sled can slide into a loading position clear of the dovetail or a travel position at least partially beneath the dovetail, and means for actuating the sled to the loading position and travel position. A method for locking the dovetail of a trailer includes moving the dovetail of a trailer into the travel position and sliding a sled from a loading position underneath the trailer to a travel position at least partially underneath the dovetail of the trailer.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of application Ser. No.13/604,284 to Patterson, filed Sep. 5, 2012, which claims the benefit ofU.S. Provisional Application No. 61/531,262 to Patterson, filed Sep. 6,2011 and entitled “Apparatus, System and Method for Dovetail LockingMechanisms,” each of which are hereby incorporated by reference in theirentireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the invention described herein pertain to the field ofvehicle trailers. More particularly, but not by way of limitation, oneor more embodiments of the invention enable an apparatus, system andmethod for dovetail trailer locking mechanisms.

2. Description of the Related Art

Flatbed trailers are often used to transport heavy or large materialssuch as farming equipment, goods and materials such as tractors, fencingand corral material, livestock equipment or hay and feeding equipment.Such trailers may also be used to transport automobiles, constructionequipment and other large and/or heavy items that would benefit fromloading and unloading on a flatbed truck using a ramp. Therefore, someflatbed trailers include a “dovetail”—a portion of the flatbed that canbe lowered to the ground in order to create a ramp at the end of thetrailer. In this way, equipment, goods and materials can be loaded ontoand unloaded from the flatbed trailer more easily. Some dovetail-typeflatbed trailers require that the ramp be lowered and raisedmechanically. Other flatbed trailers have dovetails that may be raisedand lowered hydraulically.

Traditionally, when the dovetail is in the raised position it is held inplace using steel pins. Use of pins requires slack in the receivinghole. The slack causes solid shaking when the trailer is travelling,which reduces stability of the trailer. In addition, the dovetailportion of a trailer, when secured by pins, can only accommodate alimited amount of weight. This limits the size and placement of the loadthe trailer is able to carry and negatively affects weight distributionon the trailer. Limitations of conventional dovetail trailers may alsonegatively affect towing safety.

Traditional flatbed trailers may also be susceptible to damage due tohuman error. If the dovetail is accidentally lowered while the pins arestill in place, this may cause extensive damage to the trailer that iscostly to repair. Furthermore, when a conventional dovetail trailer isrear-ended by another vehicle, the dovetail may flip upwards, with thecolliding vehicle sliding underneath the trailer causing serious damageand injury. Finally if the hydraulics that operate the dovetailmalfunction, the pins alone cannot hold the weight of the dovetail orany load placed on the top of it. In such an instance, a conventionaldovetail trailer may collapse.

Conventionally, dovetail trailers may use C-shaped brackets instead ofpins to hold the dovetail in the raised position. These C-shapedbrackets suffer from many of the same drawbacks as the pins.

For at least the limitations described above, there is a need for anapparatus, system and method for dovetail locking mechanisms.

BRIEF SUMMARY OF THE INVENTION

One or more embodiments of the invention enable an apparatus, system andmethod for flatbed trailer dovetail locking mechanisms. In someembodiments, a system for locking the dovetail of a trailer in thetravel position includes a sled for locking the dovetail of a trailer inthe travel position, a railing on the underside of the trailer toaccommodate the sled, wherein the railing extends underneath thedovetail of the trailer and wherein the sled is moveably attached to therailing such that the sled can slide into a loading position clear ofthe dovetail or a travel position at least partially beneath thedovetail, a gap in the railing to allow the dovetail to be actuated intoa loading position or a travel position, and means for actuating thesled to the loading position and travel position. In some embodiments,the sled is made of steel or alloy steel. In certain embodiments the ramis a hydraulic ram. In further embodiments, the ram at least partiallyholds the sled in place. In some embodiments, the sled includes twotubes parallel to the railing and a connecting tube that connects theparallel tubes to one another.

A method for locking the dovetail of a trailer includes moving thedovetail of a trailer into the travel position and sliding a sled from aloading position underneath the trailer and clear of the dovetail of thetrailer to a travel position at least partially underneath the dovetailof the trailer. In some embodiments the sled slides along a railing onthe underside of the trailer and the railing extends at least partiallyunderneath the dovetail of the trailer.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of the inventionwill be more apparent from the following more particular descriptionthereof, presented in conjunction with the following drawings wherein:

FIG. 1 is a perspective view of a flatbed trailer comprising one or moreembodiments of a dovetail locking mechanism.

FIG. 2 is a side view of a flatbed trailer comprising one or moreembodiments of a dovetail locking mechanism

FIG. 3 is a plan view of one or more embodiments of a flatbed trailercomprising a dovetail locking mechanism in travel position.

FIG. 4 is a plan view of a flatbed trailer comprising one or moreembodiments of a dovetail locking mechanism in loading position.

FIG. 5 is a plan view of one or more embodiments of a sled and railings.

FIG. 6 is cross section view taken along line 6-6 of FIG. 5 of one ormore embodiments of a sled in travel position.

FIG. 7 is a cross section view taken along line 6-6 of FIG. 5 of one ormore embodiments of a sled in loading position

FIG. 8 is a cross section view taken along line 8-8 of FIG. 5 of one ormore embodiments of a sled and railings.

FIG. 9 is a flowchart showing a method to secure the dovetail of aflatbed trailer for travel.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof are shown by way ofexample in the drawings and may herein be described in detail. Thedrawings may not be to scale. It should be understood, however, that thedrawings and detailed description thereto are not intended to limit theinvention to the particular form disclosed, but on the contrary, theintention is to cover all modifications, equivalents and alternativesfalling within the spirit and scope of the present invention as definedby the appended claims.

DETAILED DESCRIPTION

An apparatus, system and method for dovetail locking mechanisms will nowbe described. In the following exemplary description numerous specificdetails are set forth in order to provide a more thorough understandingof embodiments of the invention. It will be apparent, however, to anartisan of ordinary skill that the present invention may be practicedwithout incorporating all aspects of the specific details describedherein. In other instances, specific features, quantities, ormeasurements well known to those of ordinary skill in the art have notbeen described in detail so as not to obscure the invention. Readersshould note that although examples of the invention are set forthherein, the claims, and the full scope of any equivalents, are whatdefine the metes and bounds of the invention.

As used herein, “coupled” refers to either a direct connection or anindirect connection (e.g., at least one intervening connection) betweenone or more objects or components.

As used herein, “lock” or “locked” refers to the sled and/or thedovetail when in or placed in the travel position and “unlock” or“unlocked” refers to the sled and/or the dovetail when in or placed inthe loading position.

As used herein, “actuate” refers to the moving or changing the positionof a dovetail and/or sled relative to the flatbed trailer—either movingit into the travel position or the loading position.

As used in this specification and claims, the singular forms “a”, “an”and “the” include plural referents unless the context clearly dictatesotherwise. Thus, for example, reference to a railing includes one ormore railings.

Using the apparatus, systems and methods described herein, the dovetailportion of a flatbed trailer may be secured in the travel positionwithout the need for conventional pins or C-brackets. In someembodiments, the dovetail may be secured using a sled. In certainembodiments, the sled may be hydraulically actuated. In someembodiments, any hinged portion of a trailer may be secured and capableof supporting heavy loads through the use of a sled. In certainembodiments, the sled may be actuated to the locked or unlocked positionusing one or more hydraulic rams and may slide along a railing on theunderside of the trailer.

The apparatus, systems and methods described herein, prevent unwantedbending and shaking of a dovetail when the dovetail is in the travel(raised) position. Undesirable bending or shaking may occur in a trailercomprising a dovetail due to a heavy load, a collision, rough terrain orthe weight of the dovetail itself against its pins or support brackets.In addition, the apparatus, systems and methods described herein allow adovetail with the described locking mechanism to support significantlyheavier cargoes than conventional dovetails. The dovetail of theinvention typically may support loads of up to 15,000 pounds on thedovetail and lift up to about 10,000 pounds on the dovetail, dependingon the specific characteristics and size of the trailer and sled. Incomparison, a comparable conventional dovetail may only support loads ofup to about 10,000 pounds on the dovetail and lift up to about 7,500pounds on the dovetail. Furthermore, the apparatus, systems and methodsdescribed herein limit damage to the trailer due to human error bypreventing movement of the dovetail when an operator attempts to actuatethe dovetail while the sled is still in the locked position.

FIG. 1 depicts a perspective view of a flatbed trailer comprising one ormore embodiments of a dovetail locking mechanism. Trailer 10 may includewheels 15 and front end 20. Front end 20 may include gooseneck 24 and/ormay be attached to a truck, semi or cab (not shown). In someembodiments, leg(s) 22 assist in supporting trailer 10 while trailer 10is stationary or being loaded or unloaded. Leg(s) 22 may be raised andlowered mechanically, pneumatically or hydraulically. Leg(s) 22 may becontrolled by remote control or a control pad located on trailer 10. Thenumber of and location of wheels 15 will vary based on the size oftrailer 10. For example, trailer 10 may include two wheels, six wheels,eight wheels, or twelve or more wheels, or any number of wheelsappropriate for the size and type of trailer 10.

Trailer 10 may include flatbed 30 and dovetail 25′. Dovetail 25′ may bea portion of flatbed 30 and/or trailer 10 that is capable of beinglowered for loading of trailer 10. In FIG. 2, dovetail 25′ is shown atrear end 32 of flatbed 30 and depicted in alternative lowered position25 for loading. Dovetail 25 may be made of steel, wood, any combinationof the two or any other suitable materials and located at any end offlatbed 30, such as rear end 32. Dovetail 25 may be eight, nine or tenfeet in length, but shorter or longer lengths are also contemplateddepending on the size of trailer 10 and the purpose and location ofdovetail 25. In some embodiments, dovetail 25 may be on any side offlatbed 30. Dovetail 25 may be actuated into raised position 25′ fortraveling so that it is substantially even with flatbed 30. Dovetail 25may be raised and lowered using mechanical, hydraulic or pneumaticsystems well known to those of skill in the art. In some embodiments,dovetail 25 may be raised or lowered hydraulically and one or morehydraulic rams, cylinders, pistons, hoses and valves may be located onthe underside of trailer 10 for such purpose. In certain embodiments,dovetail 25 rotates on hinge 34. Hinge 34 may be any type of suitablehinge, such as a piano hinge, continuous hinge, butt hinge, pivot hinge,barrel hinge, or any other type of bearing capable of connecting twosolid objects and allowing an angle of rotation between them. In otherembodiments, hinge 34 may be any type of pivot or rotational elementthat allows dovetail 25 to move in one or more directions.

In certain embodiments, sled 35 is moveably attached to the underside offlatbed 30. In some embodiments, sled 35 is made of steel or alloysteel, such as steel tubes, piping or bars, and fitted into railings 40(shown in FIG. 2) on the underside of flatbed 30, such that it may slideinto the travel position towards dovetail 25′ to lock, or into theloading position away from dovetail 25′ (towards front end 20) tounlock. When in the travel position, sled 35 may at least partiallyextend underneath dovetail 25′. When in the loading position, sled 35may be clear of dovetail 25, 25′ so as to allow dovetail 25′ to moveinto the loading position. The size of sled 35 will depend on the sizeof flatbed 30 and dovetail 25. In certain embodiments, sled 35 may beeight feet in length of which up to four feet of length may sit belowdovetail 25′ when sled 35 in the travel position. Other sizes andlengths of sled 35 are also contemplated. In some embodiments, sled 35is substantially the same width as flatbed 30. In other embodiments,sled 35 is narrower or wider than flatbed 30.

As shown in FIG. 3, sled 35 may be actuated (moved) to the travelposition to allow dovetail 25′ to be secured into travel position 25′.As shown in FIG. 4, sled 35 may be actuated to the loading position toallow dovetail 25′ to move into loading position 25. Actuation may behydraulic, mechanical or pneumatic. Movement in other directions is alsocontemplated depending on the relative location of dovetail 25, 25′ andsled 35. In some embodiments, one or more hydraulic rams 45, whichinclude a piston and cylinder, engage and release sled 35. In certainembodiments, hydraulic cylinder of ram 45 is fully extended when sled 35is in the travel position. Hoses 47, shown in FIG. 2, may couplehydraulic ram 45 to pump 55, motor 56, and hydraulic fluid reservoir(not shown) located inside tool box 50. Tool box 50 may also house oneor more batteries and/or remote control 60 for remotely operatinghydraulic ram 45 thereby remotely engaging or releasing sled 35. Incertain embodiments, sled 35 may be powered by rechargeable batteries,the battery of the truck that is coupled to trailer 10, lithiumbatteries, solar powered batteries or any other type of powering systemwell known to those of skill in the art. Remote control 60 may be wiredor wireless and contain buttons or levers for an operator to controlhydraulic ram 45 and/or sled 35. Remote control 60 may also controloperation of dovetail 25.

Valves, switches, pistons, cylinders, pressure regulators, wiring andfittings well known to those of skill in the art may also be used withhydraulic ram 45 in connection with actuating (engaging or releasing)sled 35 and located on trailer 10, for example on the underside oftrailer 10, on the side of trailer 10 or in tool box 50. Hydraulic ram45 may be secured with a brace, such as a U-shaped brace, to preventmovement in undesirable directions, prevent shaking during movement ortravel and/or to secure hydraulic ram 45 to the underside of trailer 10and/or otherwise attach hydraulic ram 45 to trailer 10. Hoses 47 may besurrounded by protective casing.

FIG. 5 illustrates a plan view of one or more embodiments of sled 35 asseen from below. Parallel tubes 110 fit into one or more railings 40located on the side or underside of trailer 10, on the underside offlatbed 30 and/or on the underside of dovetail 25. In some embodiments,parallel tubes 110 are parallel or substantially parallel to railings 40and the length of trailer 10, such that one or more parallel tubes 110may move along railings 40 thereby sliding sled 35 into the travel orloading position. As shown in FIGS. 3-5, railings 40 may be located nearthe periphery of the underside of flatbed 30 and dovetail 25. In someembodiments, one or more railings 40 may be located in any locationbetween the outer edges of trailer 10 on the underside of trailer 10,flatbed 30 and/or dovetail 25. Parallel tubes 110 may be hollow or solidand comprised of rectangular, square, circular, oval or other shapedtubing. Lubricant may be applied to railings 40 to assist in the slidingmotion of sled 35 and/or parallel tubes 110 along railings 40.

As shown in FIG. 5, in some embodiments, connecting tubes 115 may becoupled to parallel tubes 110 and contribute to stability of sled 35when force is exerted onto sled 35 during actuation. In certainembodiments, connecting tubes 115 are perpendicular or substantiallyperpendicular to parallel tubes 110 and/or railings 40. In certainembodiments, connecting tubes 115 connect a first parallel tube 110 to asecond parallel tube 110. In some embodiments, connecting tubes 115 areset at some angle to parallel tubes 110 that provides the necessary ordesired stability to sled 35. In some common embodiments, parallel tubes110 and/or sled 35 may be about eight feet in length, wherein a firstconnecting tube 115 may then be located about 38 inches along paralleltubes 110, as measured from the end of parallel tube 110 facingsubstantially towards front end 20, and a second connecting tube 115 maybe located about 16 inches along parallel tubes 110 as measured from theend of parallel tube 100 facing substantially towards dovetail 25′. Insome embodiments, connecting tubes 115 and/or parallel tubes 110 may becomprised of about four inch by six inch rectangular tubing.

In some embodiments, pipe 120 may be coupled to connecting tubes 115 tolend additional strength and durability to sled 35. In some embodiments,pipe 120 may be substantially parallel to parallel tubes 110 andrailings 40. In some embodiments, where sled 35 and/or parallel tubes110 are about eight feet in length, pipe 120 may be about 34 inches inlength with an outer diameter of about four and a half inches. Pipe 120may be hollow or solid, round, square, oval, rectangular or any othershape sufficient to provide the desired strength and durability.

Parallel tubes 110, connecting tubes 115 and pipe 120 may be made ofsteel or any other metal, composite or material capable of withstandingthe durability and strength requirements of sled 35. Plate gussets 125may be coupled to parallel tubes 110 and connecting tubes 115. In someembodiments, plate gussets 125 are a quarter inch thick. In someembodiments, one or more hydraulic ram 45, which may include a pistonand cylinder, may be coupled to one or more connecting tubes 115 andslide sled 35 in the travel (locked) position or loading (unlocked)position.

FIGS. 6 and 7 are cross sectional views taken along line 6-6 of FIG. 5of one or more embodiments of a sled. As shown in FIGS. 6 and 7, one ormore ends of parallel tubes 110 may be tapered to assist parallel tubes110 in movement along railings 40, across gap 310 or actuating sled 35into place in the travel or loading position. Hydraulic ram 45 (shown inFIG. 5) may assist in holding or fully holding sled 35 in place while itis in the travel position (extended towards dovetail 25′). In someembodiments, the weight of dovetail 25′ and any cargo on trailer 10,flatbed 30 and/or dovetail 25′ also may assist in wedging sled 35 intoposition so it does not move during travel. In certain embodiments, theweight of dovetail 25′ and any load on trailer 10 may be sufficient tohold sled 35 in place, even if hydraulic pressure is lost in hydraulicram 45. In certain embodiments, sled 35 will not break and will holddovetail 25′ stationary in the instance that motion of dovetail 25′ isinadvertently activated while sled 35 is still in the travel position.

FIG. 7 illustrates one embodiment of sled 35 coupled to railings 40 onthe underside of flatbed 30 and dovetail 25. In FIG. 7, dovetail 25 isshown in the loading position illustrated as position 25. Parallel tube110 may be fitted into railings 40 so as to attach sled 35 to theunderside of flatbed 30 and/or dovetail 25, depending on whether sled 35is in the locked (travel) or unlocked (loading) position. In someembodiments, parallel tubes 110 have tapered end 305 to assist inconnecting tapered end 305 to railings 40 on the underside of dovetail25 or flatbed 30. Stopper 315 may assist in keeping parallel tubes 110in place and stopping the motion of parallel tubes 110 along railing 40.In some embodiments, gap 310 in railings 40 may allow dovetail 25 toactuate when sled 35 is in the loading position. When sled 35 is in thetravel position, sled 35 fills gap 310 thereby preventing movement ofdovetail 25′, as shown in FIG. 6.

As shown in FIGS. 3 and 6, in certain embodiments, sled 35 will be atleast partially below flatbed 30 and at least partially below dovetail25′ when in the travel (locked) position. As shown in FIGS. 4 and 7, incertain embodiments, sled 35 will be clear of dovetail 25 when in theloading position. In some embodiments, sled 35 will be clear of gap 310when in the loading position such that dovetail 25 is free to move andbend and/or unbend at hinge 34.

FIG. 8 is a cross section view taken along line 8-8 of FIG. 5 of one ormore embodiments of a sled and railings and further illustrates sled 35and railings 40.

FIG. 9 illustrates a flowchart of an embodiment of a method to securethe dovetail of a trailer. If sled 35 is in the travel position, in step405, sled 35 may be unlocked using hydraulic ram 45 into a loadingposition by sliding sled 35 along railings 40 away from rear end 32 andout from underneath dovetail 25′ and/or gap 310, such that hinges 34 maybe free to move. If sled 35 is initially in the loading position, step405 may be unnecessary. At step 410, rear end of dovetail 25′ maymanually, hydraulically or pneumatically be lowered to the ground tocreate a ramp for loading trailer 10, as shown in FIG. 2. In someembodiments, trailer 10 may be loaded at step 415, for example byplacing a trailer, farming and/or livestock equipment onto trailer 10.Equipment may be loaded onto either or both of flatbed 30 and dovetail25.

When the operator is ready to travel or done loading trailer 10,dovetail 25 may be moved into a raised position at step 420, as shown inFIG. 2 in alternative position 25′. When in the raised position,dovetail 25′ may form one long platform with flatbed 30. At step 425,sled 35 is moved into the travel (locked) position by actuating sled 35along railings 40, such that parallel tubes 110 proceed past gap 310(shown in FIG. 6) and into railings 40 on dovetail 25′. In someembodiments, parallel tubes 110 may proceed to a position where onequarter, one half, or three quarters of their length are along railings40 located on dovetail 25. In other embodiments, parallel tubes 110 mayproceed to any other position underneath dovetail 25 and flatbed 30 suchthat the weight of dovetail 25′ and any load on either of them aresupported. In some embodiments, at travel step 430, trailer 10 is readyfor travel once sled 35 is in the travel (locked) position. If leg(s) 22have been lowered during loading, they may be raised prior to travel.

As would be well understood by those of ordinary skill in the art,trailer 10 may also be unloaded using steps similar and/or the reverseof those described elsewhere herein.

The inventions described herein increase the stability and strength ofconventional dovetail trailers. The sled of the invention reducesshaking of flatbed trailers when travelling since slack from pins iseliminated. The inventions described herein also increase the weightthat the dovetail portion of a flatbed trailer is able to support.Damage to flatbed trailers due to human error or in collisions is alsosignificantly reduced through the use of the inventions describedherein, as the sled will not allow the dovetail portion of a flatbedtrailer to move while the sled is in the travel position.

Further modifications and alternative embodiments of various aspects ofthe invention may be apparent to those skilled in the art in view ofthis description. Accordingly, this description is to be construed asillustrative only and is for the purpose of teaching those skilled inthe art the general manner of carrying out the invention. It is to beunderstood that the forms of the invention shown and described hereinare to be taken as the presently preferred embodiments. Elements andmaterials may be substituted for those illustrated and described herein,parts and processes may be reversed, and certain features of theinvention may be utilized independently, all as would be apparent to oneskilled in the art after having the benefit of this description of theinvention. Changes may be made in the elements described herein withoutdeparting from the spirit and scope of the invention as described in thefollowing claims. In addition, it is to be understood that featuresdescribed herein independently may, in certain embodiments, be combined.

What is claimed is:
 1. A system for locking a dovetail of a trailer withrespect to a flatbed of the trailer, the system comprising: a flatbed,the flatbed comprising a first railing formed on a periphery of anunderside of the flatbed and extending to about an end of the flatbed; adovetail pivotally connected to the end of the flatbed at a pivot point,the dovetail comprising a second railing formed on a periphery of anunderside of the dovetail, wherein the dovetail is pivotable between: atravel position, wherein the first railing and second railing aresubstantially aligned, and a gap is formed between the first railing andthe second railing below the pivot point; and a loading position,wherein the dovetail is pivoted downward about the pivot point, suchthat the gap is at least partially closed; and a sled, the sled beingslideably connected to the flatbed, and moveable via an actuating meansattached to the flatbed, the sled comprising an elongate sliding memberslidably engaged within the first railing, wherein the actuating meansmoves the sled between: a locked position, wherein when the dovetail isin the travel position, the sliding member is moved toward the dovetailso as to fill the gap and engage both the first and second railings,thereby preventing the dovetail from pivoting relative to the flatbed;and an unlocked position, wherein the sliding member is moved away fromthe dovetail so as to clear the gap, thereby allowing the dovetail topivot relative to the flatbed into the loading position.
 2. The systemof claim 1, wherein the means for actuating the sled is a hydraulic ram.3. The system of claim 1, wherein the sled comprises a tube parallel tothe railings, wherein the parallel tube is slideably engaged within thefirst railing, and wherein the parallel tube has a tapered end.
 4. Amethod for locking a dovetail of a trailer with respect to a flatbed ofthe trailer, the method comprising: pivoting a dovetail of a trailerinto a travel position such that a first railing on a periphery of anunderside of the dovetail is substantially aligned with a second railingon a periphery of an underside of a flatbed of the trailer, wherein agap is formed between the first railing and the second railing when thedovetail is in the travel position; and actuating an elongate sledmoveably attached within the second railing from a loading positionunderneath the flatbed and clear of the gap to a locked position,wherein the sled fills the gap and engages both the first and secondrailings in the locked position, the sled thereby preventing thedovetail from pivoting relative to the flatbed in the locked position.5. The method of claim 4, wherein the elongate sled is hydraulicallyactuated.
 6. The method of claim 5, wherein the elongate sled isactuated by remote control.
 7. The method of claim 4, wherein theelongate sled comprises a tube parallel to the second railing, theparallel tube moveably attached within the second railing.
 8. The methodof claim 4, wherein the dovetail comprises a plurality of firstrailings, the flatbed comprises a plurality of second railings, and theelongate sled is engaged within the plurality of first and secondrailings in the locked position.
 9. A method for locking a dovetail of atrailer with respect to a flatbed of the trailer, the method comprising:pivoting a dovetail of a trailer into a travel position such that afirst railing on a periphery of an underside of the dovetail issubstantially aligned with a second railing on a periphery of anunderside of a flatbed of the trailer, wherein a gap is formed betweenthe first railing and the second railing when the dovetail is in thetravel position; and actuating an elongate sled moveably attached on theunderside of a periphery of the trailer from a loading position clear ofthe gap to a locked position, wherein the sled fills the gap and engagesboth the first and second railings in the locked position, the sledthereby preventing the dovetail from pivoting relative to the flatbed inthe locked position.
 10. The method of claim 9, wherein the elongatesled is hydraulically actuated.
 11. The method of claim 10, wherein theelongate sled is actuated by remote control.
 12. The method of claim 9,wherein the dovetail comprises a plurality of first railings, theflatbed comprises a plurality of second railings, and the elongate sledis engaged within the plurality of first and second railings in thelocked position.